Surfactant and neonatal hemodynamics during the postnatal transition.

Surfactant replacement therapy (SRT) has revolutionized the management of respiratory distress syndrome (RDS) in premature infants, leading to improved survival rates and decreased morbidity. SRT may, however, be associated with hemodynamic changes, which can have both positive and negative effects on the immature cardiovascular system, during the transitional adaptation from fetal to extrauterine environment. However, there is a relative paucity of evidence in this domain, with most of them derived from small heterogeneous observational studies providing conflicting results. In this review, we will discuss the hemodynamic changes that occur with surfactant administration during this vulnerable period, focusing on available evidence regarding changes in pulmonary and systemic blood flow, cerebral circulation and their clinical implications.

Preliminary study of automated oxygen titration at birth for preterm infants.

OBJECTIVE: To study the feasibility of automated titration of oxygen therapy in the delivery room for preterm infants. DESIGN: Prospective non-randomised study of oxygenation in sequential preterm cohorts in which FiO2 was adjusted manually or by an automated control algorithm during the first 10 min of life. SETTING: Delivery rooms of a tertiary level hospital. PARTICIPANTS: Preterm infants <32 weeks gestation (n=20 per group). INTERVENTION: Automated oxygen control using a purpose-built device, with SpO2 readings input to a proportional-integral-derivative algorithm, and FiO2 alterations actuated by a motorised blender. The algorithm was developed via in silico simulation using abstracted oxygenation data from the manual control group. For both groups, the SpO2 target was the 25th-75th centile of the Dawson nomogram. MAIN OUTCOME MEASURES: Proportion of time in the SpO2 target range (25th-75th centile, or above if in room air) and other SpO2 ranges; FiO2 adjustment frequency; oxygen exposure. RESULTS: Time in the SpO2 target range was similar between groups (manual control: median 60% (IQR 48%-72%); automated control: 70 (60-84)%; p=0.31), whereas time with SpO2 >75th centile when receiving oxygen differed (manual: 17 (7.6-26)%; automated: 10 (4.4-13)%; p=0.048). Algorithm-directed FiO2 adjustments were frequent during automated control, but no manual adjustments were required in any infant once valid SpO2 values were available. Oxygen exposure was greater during automated control, but final FiO2 was equivalent. CONCLUSION: Automated oxygen titration using a purpose-built algorithm is feasible for delivery room management of preterm infants, and warrants further evaluation.